ABSTRACT The environmental impacts are commonly quantified in the EIA studies by rating, ranking and scaling. The National EIA Guidelines, 1993, Nepal provides a guideline to score the impacts in terms of magnitude, extent, and duration. This step is commonly known as impact prediction in the EIA process. The predicted scores are multiplied by the weightage value of the resource; likely to be affected. The application of the weightage transforms the predicted values of the impacts into their “significance”—a concept used in the environmental decision making. In other words the significance value entails assignment of relative judgment values to the impacts. The impacts, thus, can ranked based on their significance. The impact ranking is more useful in evaluating the socio-economic impacts. Unlike air, water and noise quality, which can be assessed against established standards; the socio-economic impacts do not have standard scale and are difficult to rank. Importance weighting of socio-economic impacts are commonly determined by the consensus obtained from the interaction with the local people, agencies, NGOs and experts. The impact ranking in the EIA process is unavoidable, firstly to prioritize the urgent environmental issues and design mitigation measures accordingly and also provide coherent linkages among the issues, and plan monitoring and auditing linkage with the proposed mitigation measures. Furthermore, it also provide strong basis of decision making, and thus facilitate the decision makers. The process of impact prediction, determination of significance and ranking were applied in the EIA of Indrwati-3 Hydroelectric Project, which is one of the successful cases of EIA in Nepal. The authors believe that the impacts predicted and quantified through this method are being focussed to more on the local concerns, since it seeks an active involvement of the local people who are likely to be affected.
Cite this paper
nullR. Khadka, A. Mathema and U. Shrestha, "Determination of Significance of Environmental Impacts of Development Projects: A Case Study of Environmental Impact Assessment of Indrawati-3 Hydropower Project in Nepal," Journal of Environmental Protection, Vol. 2 No. 8, 2011, pp. 1021-1031. doi: 10.4236/jep.2011.28117.
 Australian and New Zealand Environment and Conservation Council, 1991. A national Approach to Environmental Impact Assessment in Australia, Anzecc Secretariat, Australia
 Beanlands, G.E and Duinker, P.N, 1983. An ecological framework for environmental impact assessment in Canada, Dalhousie University and FEARO Canada
 Canadian Federal Environmental Assessment Review Office (REARO), 1986. Environmental Screening and Initial Assessment Guidelines, FEARO, Canada.
 Canter, L.W 1996. Environmental Impact Assessment; McGraw-HILL Book Company, New York
 Gilpin, a 1995. Environmental Impact Assessment: Cutting age for the 21st Century; Cambridge University Press, London
 Government of Nepal, 1997. Environmental Protection Regulation; Government Press Nepal.
 Hauge,P.T et.al, 1984. Determining the significance of Environmental issue under the National Environmental Policy Act; Journal of Environmental Management 18 15-24
 Khadka R.B and H. Shrestha, 2008. The Scoping Process for Environmental Impact Assessment of Project: A case study of outer-ring road project in Nepal-Based on Local [People’s perception, The International Journal of Environmental, Cultural Economic and Social Sustainability: Vol 4, Number 3 pp 25-36
 Khadka R.B and Steve Gorzula, 2010. Environmental Impact Assessment (EIA): Pokhara University, Nepal, Page 1-136.University Publication.
 National Planning Commission, Government of Nepal and IUCN, 1993. National Environmental Impact Assessment Guidelines, NCSIP, Kathmandu.
 National Hydropower Company, Pvt, 2002. Environmental Impact Assessment (EIA) of Indrawati-3 Hydropower Project- Approved by the government of Nepal.
 National Hydropower Pvt, 2007. EMP Monitoring Report of Indrawati Hydropower Project; a report to Government of Nepal.
 Rau, G.J and David C. Wooten, 1980. Environmental Impact Assessment Handbook: McGraw-HILL Book Company, New York.
 Sadar, M, H, 1996. Environmental Impact Assessment: Carleton University Press for Impact Assessment Center, Canada.
 Sippe, R 1999. Criteria and Standard for Assessing Significant Impact: In Judith Petts edit. Handbook of Environmental Assessment; Vol 1, Blackwell Science LtD, 1999.
 Shah Consult International (P) LtD, 1997. Feasibility study and Initial Environmental Examination of Indrawati-3 Hydropower project for the Government of Nepal
 Thompson, M.A, 1990. Determining Impact Significance in EIA: A review of 24 methodologies, Journal of Environmental Management, 30 235-50.